The Algonquin tribes are said to have been included within lines extending from Cape Hatteras to the head of the Mississippi, and thence eastward to the coast north of Newfoundland, and thence along the Atlantic shore to the cape first mentioned.[269:B] The bulk of the Indians within this triangle spoke various dialects of the same generic language. The thirty tribes of Indians comprised within the Powhatan confederacy, south of the Potomac, at the time of the landing at Jamestown, are conjecturally estimated at about eight thousand souls, being one to the square mile.[269:C] The population of the mountain country was probably sparser than that of the country east of the mountains. The number of square miles in Virginia at the present day is upwards of sixty-five thousand. The number of warriors belonging to the tribes tributary to Virginia in 1669, as has been before mentioned, was seven hundred and twenty-five, and their proportion to the entire population being reckoned as three to ten, their aggregate number was about twenty-four hundred. Thus in about sixty years the diminution of their numbers amounted to about five thousand six hundred; of these, part had perished from disease, exposure, famine, and war; the rest were driven back into the wilderness. In the year 1670 complaints were made to the general court by members of the council and others, being gentlemen, of the counties of York, Gloucester, and Middlesex, representing their apprehensions of danger from the great number of felons, and other desperate villains, sent hither from the prisons of England. Masters of vessels were prohibited from landing any such convicts or jail-birds. In 1671 Captain Bristow and Captain Walker were required to give security in the sum of one million pounds of tobacco and cask, that Mr. Nevett should send out the Newgate-birds within two months. Mr. Jefferson[270:A] has made the following remark: "The malefactors sent to America were not sufficient in number to merit enumeration as one class out of three which peopled America. It was at a late period of their history that the practice began. I have no book by me which enables me to point out the date of its commencement; but I do not think the whole number sent would amount to two thousand." And he supposed that they and their descendants did not, in 1786, exceed four thousand, "which is little more than one-thousandth part of the whole inhabitants." Mr. Jefferson appears to have been mistaken in his opinion, that malefactors were not sent over until a late period in the annals of Virginia; and he probably underrated the number of their descendants.